B6—Lancaster Farming, Saturday, May 2,1981 If you are catching a flight to Miami, singing in the choir or getting married, the question is foolish you’d better be on time or you’re out of luck. Books have been written about the importance of correct tuning in breeding, milking, and many other aspects of dairy farming. Correctly timing the planting and harvesting of crops has a profound bearing on yields and profitability. But the effect of late planting is difficult to measure, especially when it is complicated by other conditions like rain, heat, drought or other things that wg can’t control. We do have some tools the measure the effect on yield of late planted corn. We’ve known for a long time that com yields are greatly reduced by late planting. We also know that any reduction in the optimum stand or population mil also reduce yields. A formula to help us measure the reductions has been computerized by lowa State University scientists and can now be used on the TI-59 programmable calculator. We can quickly estimate the anticipated yield of com planted later than the ideal date (about April 25 in southeastern Pennsylvania) and/or having a population density less than optimal (26,000 plants per acre). This can help us decide whether to replant to a higher population if the stand is poor, or accept a somewhat reduced yield. Replanting will mean planting much later, of course, which will also affect yields. The dilemma is in deciding which is the lesser evil, low population or late planting. Using the calculator program, tables have been worked out to help visualize the effects, both individually and combined. They were com piled on the assumption that the optimum yield potential is 150 bushels of Tl>e Dairy Business By Newton Bair Does It pay to be on time? shelled corn per acre, with a maximum population of 26,000 plants at planting. Table I shows the effect on yield of reduced stand alone, when the com was planted early, at or near the optimum date of April 29 in southeastern Pennsylvania. The only effect is from reduced stand. There is a rapid reduction in yield potential as the stand is reduced. Ptants/Acre 26 000 22 000 18 000 14 000 The combined effect of reduced stand and delayed planting can be seen in Table 11. The right hand column shows the percentage of maximum yield potential resulting from both later planting and reduced stand. These combined effects are more serious than either one above. Planting com two weeks later than the optimum time reduces yields by 6 percent in addition to the lower yield from reduced population. Plants/Acre 26 000 22 000 18 000 14000 Table 111 shows a reduction of 17 percent in yield due to planting 30 days after optimum. Added to the reductions due to lower population, the yields are seriously reduced. Ptants/Acre Yield Potential 26 000 125 bu 22 000 121 bu 18000 113 bu UOOO 100 bu How can this information be used? Suppose you’ve planted early but hail, cutworms or stalkborers or some other unforseen disaster has reduced the stand from your original 24,000 plants to an actual count estimate of 14,000 per acre. Your yield potential is now reduced to 80 percent or about 120 bushels per acre. Your decision on whether to replant or accept the reduced yield will depend on just how much time has elapsed between the original planting and replanting. If you can replant by May 15 you might increase the yield potential to 90 percent optimum with a full stand. But if replanting is four weeks late, around the end of May, the most you could expect would be about 83 percent of your potential. Any decision you make must consider other variables. The calculations of this or any program designed to aid in complex decisions can only be valid within the assumptions and constraints built into it. It must therefore be used with discretion and tempered with common sense. DRAINAGE PROBLEMS? COCALICO EQUIPMENT HAS THE TWO MACHINES TO HANDLE YOUR DRAINAGE PROBLEMS. ★ Both machines Equipped with Laser Beam Grade Control Drainage Pays High Returns COMPARE investment Annualßet urn Even with the conservative fig- Farmßulldmgs . ; 2 1U% ures shown here, it’s obvious that land drainage should top farmers’ Bonds 6.1% lists of investment priorities. immf cocalico equipmentco. \■ 1 c Y DRAINAGE & EXCAVATING \y RD DENVER, PA 17517 PH: 215*267-3808 TABLE I Effect on Corn Yield by Reduced Stand Corn Planted at Optimum Time (April 29) Yield Potential 150 bu 146 bu 135 bu 120 bu TABLE II Effect on Corn Yield toy Reduced Stand corn planted May 15 (2 weeks (ate) Yield Potential 141 bu 137 bu 127 bu 112 bu TABLE 111 Effect on Corn Yield by Reduced Stand Corn Re-planted May 29 (4 weeks late) % Potential Yield by Reduced Stand 100% 97% 90% 80% Late Plant 100% 100% 100% 100% % Potential Yield by Reduced Stand 94% 91% 84% 74% Late Plant 94% 94% 94% 94% % Potential Yield by Reduced Stand 83% 80% 75% 67% Late Riant 83% 83% 83% 83% ★ We Stock Heavy Grade Tubing which Exceeds SCS Specifications. In sizes 4", 6", 8". 1C" and 12". NOW AVAILABLE 15" & 18" Tubing ★ Also Pipe And Fittings For Tile Outlet Terraces. STRIKE IT RICH! SOI IT WITH A LANCASTER FARMING CLASSIFIED dk
Significant historical Pennsylvania newspapers